I have a physical machine running Vista Ultimate 64bit. This machine has a static IP of 192.168.1.100. There are maybe 10 nodes on the entire network, and the DHCP scope runs from .75-.99 off of the gateway, which is 192.168.1.1, is a PIX, and it's a /24 network
On this machine, I have have VMware Server 2.0.0, Build 122956. I have 2 Ubuntu VMs, an XP Pro VM, a Server 2008 VM, and a Server 2003 VM all created on this machine. I have not had an issue with the Ubuntu VMs, though I do not use them frequently. I built VMs for XP, 2003, and 2008 for studying/testing purposes. The servers have static IPs, and they are .10 and .11. XP is DHCP.
Anytime I leave the XP VM or the Server 2003 VM running for any length of time (sorry, I do not know precisely how long, but I'd say longer than 20-30 minutes), my Vista OS loses at a minimum, internet connectivity, DNS resolution, and I get a Network Error, "Windows has detected an IP address conflict." I have not tested the XP VM, but the 2003 VM still has internet connectivity. It cannot ping the Vista host by name or IP.
This ONLY happens on this Vista machine when the VM hosts are running. Once I close the hosts, I can reset the adapter, and everything is fine again.